Remote control systems are commonly used in conjunction with a wide variety of electronic devices including: stereo sets, television receivers, cassette tape decks, video tape decks, compact disk players, digital video disk players, and the like. Such systems generally consist of a transmitter which is positioned remotely from a controlled electronic device and which, when appropriate command keys are pressed by a user, transmits a remote control signal to a receiver in the controlled device. The received remote control signal is then decoded to control the electronic device as intended by the user.
More recently, at least one remote control system has been designed employing voice control commands instead of control commands entered through keys. U.S. Pat. No. 5,199,080 issued to Kimura et al., for example, discloses a voice-operated remote control system wherein a voice command is spoken into the microphone of a remote hand-held device. The hand-held device includes circuitry and other means to convert the audio signal into digital pattern data. The hand-held device also includes means to compare the pattern data to other pattern data stored within the remote device. Then, remote control signals based on a recognized command are generated within the device and transmitted to a controlled device wherein they are decoded.
However, the present inventor has come to appreciate that such prior art voice-operated remote control systems are disadvantageous for several reasons. One disadvantage of such prior art systems is that it is expensive to manufacture apparatus for converting voice commands, storing and comparing pattern data, and generating and transmitting signals such that all the necessary apparatus fits within a hand-held remote device which is not too large or unwieldy. Another disadvantage is that prior art systems have problems of power consumption within the hand-held device. Because the hand-held device is powered by battery, every time it is used, each of the several functions performed within the device consumes a significant portion of the limited power supply. Although methods have been employed to reduce the drain of power within the device, such as hardware or software designed for “active power-down” of the remote, the present inventors have recognized a need for a voice-operated remote control system which reduces the number of functions performed within the remote device, which further reduces power consumption, and which further lowers the cost of manufacture.